Organic semiconductor device and process of manufacturing the same

ABSTRACT

The present invention is for providing a sophisticated active matrix type organic semiconductor device. A first electrode  102  is formed on an insulated surface. A second insulated film  104  is formed on the first electrode  102  via a first insulated film  103.  An organic semiconductor film is formed on an opening part formed on the second insulated film  104  and the second insulated film  104.  An organic semiconductor film  105  is obtained by polishing the same until the second insulated film  104  is exposed. Furthermore, by forming a second electrode  106  and a third electrode  107  on the organic semiconductor film  105,  an organic semiconductor device of the present invention can be obtained.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an organic semiconductor devicecomprising a thin film transistor (TFT) using an organic semiconductorfilm and a process of manufacturing the same. In this specification, theorganic semiconductor device denotes the device capable of functioningby utilizing the characteristics of organic semiconductor materials onthe whole, that is, it refers to active matrix type semiconductor devicewith a TFT provided on the same substrate. Specifically, device using aluminescent element having a film containing an organic compound(hereinafter referred to as the “organic compound layer”) between a pairof electrodes, capable of obtaining the fluorescence or phosphorescenceby applying an electric field thereto (hereinafter referred to as the“luminescent device”), electro-optical device such as a liquid crystaldisplay device, electric appliances with the electro-optical devicemounted as a part thereof, are also included in the range.

[0003] 2. Description of the Related Art

[0004] In various kinds of semiconductor device storing a semiconductorelement, such as a television image receiving device, a personalcomputer and a portable phone, a display for displaying characters andimages is indispensable as a means for recognizing the information by auser. In particular, recently, a flat plate type display (flat paneldisplay) represented by a liquid crystal display device, utilizing theelectro-optical characteristics of the liquid crystal has been usedactively.

[0005] As a form of a flat panel display, an active matrix drivingmethod of displaying an image by providing a TFT per each pixel andsuccessively writing a data signal, is known. The TFT serves as aprerequisite element for realizing the active matrix driving method.

[0006] Although such a TFT has been produced so far mostly utilizing aninorganic semiconductor material such as an amorphous silicon and acrystalline silicon, since the processing temperature in themanufacturing process for a semiconductor layer, or the like exceeds350° C. in the case of forming the TFT using the material, a problem isinvolved in that a lot of useful substrate substances cannot be used inother cases.

[0007] In contrast, a method of producing the TFT with an organicsemiconductor material has been proposed. In this specification, anorganic compound showing the semiconductor-like electric property ofabout a 10⁻² to 10¹⁶ Ωcm specific resistance is referred to as theorganic semiconductor material, and a film formed with the organicsemiconductor material is referred to as the organic semiconductor film.Moreover, the TFT produced using the organic semiconductor material isreferred to as the organic TFT.

[0008] Since the organic TFT can be formed by the deposition method, thespin coating method, or the like of the organic semiconductor material,film formation can be enabled at a low temperature. Among the organicsemiconductor materials, according to a soluble organic semiconductormaterial synthesized so as to be soluble in an organic solvent, coatingmethods such as the casting method and the spin coating method offorming a film by developing the solution on the substrate and dryingcan be utilized, and thus simplification of the manufacturing processcan be expected. Furthermore, it is excellent in that the semiconductorfilm can be formed immediately without the need of the post treatmentother than the drying operation.

[0009] However, in the case of forming a plurality of organic TFTsformed by a soluble organic semiconductor material, the patterningoperation is difficult, and the method therefore is limited.

SUMMARY OF THE INVENTION

[0010] Accordingly, an object of the present invention is to provide afurther sophisticated active matrix type organic semiconductor device byproviding a method for forming a finer structure compared with theprinting method and the ink-jet method, which have ever been used as amethod for patterning a liquid material in the case of forming anorganic. TFT using such a soluble organic semiconductor material.Furthermore, another object is to provide an electric appliance havingthe organic semiconductor device.

[0011] In order to solve the above-mentioned problems, the configurationof the present invention comprises a first electrode formed in contactwith an insulated surface, a first insulated film formed in contact withthe first electrode, a second insulated film formed in contact with thefirst insulated film, having an opening part on the first electrode, anorganic semiconductor film formed in the opening part in contact withthe first insulated film and the second insulated film, and a secondelectrode and a third electrode formed in contact with the organicsemiconductor film but without contact with each other.

[0012] The organic semiconductor film formed in the opening part isformed on the opening part and the second insulated film and afterwards,the organic semiconductor film formed on the second insulated film inthe part other than the opening part is eliminated, and thus it has thesame surface as that of the second insulated film.

[0013] Moreover, since the organic semiconductor film is formed in theopening part provided by completely eliminating the second insulatedfilm disposed on the first electrode for functioning as the gateelectrode, it is formed in contact with the first insulated film as wellas it has a structure to be formed at a position superimposed with thefirst electrode via the first insulated film.

[0014] Here, by forming the rim of the opening part with a 45 to 60degree taper angle, film formation of the organic semiconductor materialcan be facilitated.

[0015] Furthermore, the second electrode and the third electrodefunction each as the source electrode and the drain electrode in theorganic TFT, they are formed with the same material without contact witheach other. As to the material of the source electrode and the drainelectrode in the present invention, since most of the semiconductormaterials are a p type semiconductor for transporting the positive holeas the carrier, it is preferable to use a metal with a large workfunction for obtaining the ohmic contact with the semiconductor layer.

[0016] Specifically, metals capable of forming an electrode using theexisting photolithography, such as gold, platinum, chromium, palladium,aluminum, indium, molybdenum and nickel, alloys using these metals, orthe like are preferable.

[0017] Moreover, as the organic semiconductor material used in thepresent invention, a π electron conjugate system polymer material havingthe skeleton of a conjugate double bond is preferable. Specifically,soluble polymer materials such as a polythiophene, a poly(3-alkylthiophene) and a polythiophene derivative can be used.

[0018] Additionally, as the organic semiconductor material usable in thepresent invention, materials capable of forming an organic semiconductorfilm by treating after film formation of a soluble precursor can bepresented. As such an organic semiconductor material obtainable via sucha precursor, a polythienylene vinylene, a poly(2,5-thienylene vinylene), a polyacetylene, a polyacetylene derivative, a polyallylene vinylene,or the like can be presented.

[0019] In the present invention, these soluble organic semiconductormaterials and the precursors are totally referred to as the solubleorganic semiconductor materials. However, in the present invention, notonly the above-mentioned materials, but also known organic semiconductormaterials can be used as well.

[0020] At the time of converting the precursor to the organicsemiconductor, not only the heating treatment but also addition of areaction catalyst such as a hydrogen chloride is executed. In the casesuch a treatment is needed, a problem of corrosion of an electrode, orthe like is involved, however, according to the structure of the organicTFT described in the present invention, there is no concern of theproblem.

[0021] Moreover, as the representative solvents for dissolving thesesoluble organic semiconductor materials, a toluene, a xylene, achlorobenzene, a dichlorobenzene, an anisole, a chloroform, adichloromethane, a y butyl lactone, a butyl cellsolve, a cyclohexane, anNMP (N-methyl-2-pyrolidone), a cyclohexanone, a 2-butanone, a dioxane, adimethyl formamide (DMF) a THF (tetrahydro furan), or the like, can bepresented.

[0022] Furthermore, a process of manufacturing of the present inventionfor realizing such a configuration, comprises the steps of forming afirst electrode on an insulated surface, forming a first insulated filmon the first electrode, forming a second insulated film on the firstinsulated film, forming an opening part at a position with the secondinsulated film superimposed on the first electrode via the firstinsulated film, forming an organic semiconductor film on the openingpart and the second insulated film, polishing the organic semiconductorfilm until the second insulated film is exposed, and forming a secondelectrode and a third electrode without contact with each other bypatterning the conductive film after formation of a conductive film onthe organic semiconductor film.

[0023] According to the above-mentioned process of manufacturing, anorganic TFT of the present invention can be produced.

[0024] In the case of forming an organic semiconductor film using asoluble organic semiconductor material in the present invention, it ispreferable to use the spin coating method.

[0025] Moreover, as a method of eliminating the organic semiconductorfilm formed in the part other than the opening part in the presentinvention, the polishing method such as the mechanical method, thechemical method and the CMP (chemical mechanical polishing) method canbe presented. Furthermore, in the present invention, the ashing methodcan be used as well.

[0026] In the case the CMP method is used in the present invention, as apolishing agent (slurry), those including the abrasive grains such as analumina (Al₂O₃), a silica (SiO₂ powder) and a cerium oxide (CeO₂) can beused. Moreover, as a solution for dispersing these abrasive grains,acidic or alkaline solutions such as a sulfuric acid, a nitric acid andan ammonium solution may be used, however, pure water can be used aswell. Moreover, a surfactant can be used as needed. In the CMP processof the present invention, the organic semiconductor film is polisheduntil the surface of the second insulated film is-exposed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027]FIG. 1 is a diagram for explaining the structure of an organic TFTof the present invention.

[0028]FIGS. 2A to 2E are a diagram for explaining a process ofmanufacturing an organic TFT of the present invention.

[0029]FIG. 3 is a diagram for explaining the structure of a pixel partof a luminescent device.

[0030]FIGS. 4A to 4D are a diagram for explaining a process ofmanufacturing a luminescent device.

[0031]FIGS. 5A to 5C are a diagram for explaining a process ofmanufacturing a luminescent device.

[0032]FIGS. 6A and 6B are a top view and a circuit diagram of a pixelpart of a luminescent device.

[0033]FIG. 7 is a diagram for explaining the structure of a pixel partof a liquid crystal display device.

[0034]FIGS. 8A to 8D are a diagram for explaining a process ofmanufacturing a liquid crystal display device.

[0035]FIGS. 9A and 9B are a top view and a circuit diagram of a pixelpart of a liquid crystal display device.

[0036]FIGS. 10A and 10B are views for explaining the sealing structureof a luminescent device.

[0037]FIGS. 11A to 11H are views showing examples of electricappliances.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0038] An embodiment of the present invention will be explained indetail in view of the process of manufacturing an organic TFT in thestructure shown in FIG. 1 with reference to FIG. 2. Since the numeralsused in FIG. 1 and FIG. 2 are same, they can be referred to as needed.

[0039] In FIG. 2A, a first electrode 101 is formed by patterning aconductive film formed on a substrate 101. As the substrate 101, a glasssubstrate, a quartz substrate, a ceramic substrate, or the like can beused. Moreover, a silicon substrate, a metal substrate or a stainlesssteel substrate with an insulated film formed on the surface can be usedas well. Moreover, a plastic substrate having a thermal resistance tothe processing temperature of this embodiment can also be used.

[0040] Moreover, the first electrode is made of a conductive materialcomprising one or a plurality selected from the group consisting of a W,an Mo, a Ti and a Ta. The first electrode 102 serves as the gateelectrode of the organic TFT.

[0041] After formation of the first electrode 102, a first insulatedfilm 103 is formed. As the first insulated film 103, a silicon oxidefilm, a silicon oxide nitride film, or an insulated film containing asilicon is used, and it is formed by the plasma CVD method or thesputtering method by a 50 to 150 nm thickness.

[0042] Next, an insulted film is formed on the first insulated film 103.As the insulating material used here, inorganic materials containingsilicon such as a silicon oxide, a silicon nitride, a silicon oxidenitride and a laminated film of a combination thereof as well as organicmaterials such as an acrylic, a polyimide, a polyamide, a polylmideamide and a BCB (benzocyclo butene) can be used.

[0043] In the case an inorganic material is used, the film is formed bythe plasma CVD method, the sputtering method or the deposition method.In the case an organic material is used, the film is formed by the spincoating method, the printing method, or the ink-jet method. The filmthickness is about 10 to 500 nm.

[0044] By forming a resist mask 104 of a desired pattern after formationof the insulated film and etching by the photolithography method, asecond insulated film 105 having an opening part can be formed on thefirst electrode 102 as shown in FIG. 2B.

[0045] Next, an organic semiconductor film 106 is formed on the firstelectrode 102 and the second insulated film 105. At the time, it ispreferable to form the organic semiconductor film 106 by a filmthickness thicker than that of the second insulated film 105 as shown inFIG. 2C.

[0046] Next, the organic semiconductor film 106 formed on the secondinsulated film 105 is eliminated. As the method for partiallyeliminating the organic semiconductor film 106, not only the polishingmethod (chemical method, the mechanical method, the CMP method) but alsothe ashing method can be used. In this embodiment, the elimination isexecuted by the CMP method.

[0047] As the polishing agent (slurry) used in the CMP method, oneobtained by dispersing alumina (Al₂O₃) or silica (SiO₂ powder) abrasivegrains in a nitric acid or an ammonium solution with a surfactant(Triton X) added, can be used. At the time, the polishing operation isexecuted with a 300 g/cm² pressure applied from a polishing pad. Thepressure at the time of the polishing can be selected in a range ofabout 100 g/cm² to 500 g/cm².

[0048] As to the elimination of the organic semiconductor film by theCMP method, the eliminating operation is executed until the surface ofthe second insulated film 105 is exposed so as to leave only the organicsemiconductor film formed in the opening part on the first electrode.

[0049] Accordingly, a channel area 107 made of an organic semiconductorfilm is formed on the first electrode at a position in contact with thesecond insulated film 105 as shown in FIG. 2D.

[0050] Furthermore, as shown in FIG. 2E, a second conductive film isformed on the second insulated film 105 and the channel area 107 usingthe deposition method. By patterning the second conductive film by thephotolithography, a source electrode 108 and a drain electrode 109 areformed. The second conductive film is formed by a 10 to 200 nm filmthickness.

[0051] The size of the source electrode 108 and the drain electrode 109is (500×30 μm²). In this case, the channel width W is 500 μm. The gapbetween the source/drain electrodes, that is, the channel length L is 30μm.

[0052] As mentioned above, the organic TFT having a structure with thechannel area 107 provided separately can be formed as shown in FIG. 1.Accordingly, a fine structure pattern can be formed using a polymermaterial, which can hardly be patterned despite a high carrier movingdegree. As a result, since the size (in particular, the channel width)of the organic semiconductor TFT can be made smaller, the integrationdensity can be improved.

EXAMPLES Example 1

[0053] In this example, luminescent device of an active matrix drivingmethod using an organic TFT explained in the embodiment will beexplained. FIG. 3 shows the structure of a pixel part of the luminescentdevice. Moreover, the process of manufacturing the luminescent devicewill be explained with reference to FIGS. 4 and 5.

[0054] In FIG. 3, the channel area 305 is formed on the gate electrode302 provided on the substrate 301 via the gate insulated film 303, andthe source electrode 306 and the drain electrode 307 are formed incontact with the channel area 305. The channel area 305 is formed in theopening part provided in the first interlayer insulated film 304.Moreover, in this example, the organic TFT is referred to as a currentcontrolling TFT 308. Since the process of manufacturing the organic TFTso far is explained in the embodiment, details thereof are not explainedhere.

[0055] After formation of the source electrode 306 and the drainelectrode 307, a second interlayer insulated film 309 is formed. Thesecond interlayer insulated film 309 is made of an organic resinmaterial such as a polyimide, an acrylic and a polyimide amide. Bycoating these materials with a spinner and, heating and baking, orpolymerizing, the surface thereof can be flattened. Moreover, since theorganic resin material in general has a low dielectric constant, theparasitic capacity can be reduced.

[0056] Next, for preventing adverse effect of degassing from the secondinterlayer insulated film 309 on the luminescent element, a thirdinterlayer insulated film 310 is formed on the second interlayerinsulated film 309. The third interlayer insulated film 310 comprises aninorganic insulated film. Representative examples thereof include asilicon oxide film, a silicon oxide nitride film, a silicon nitridefilm, or a laminated film of a combination thereof. It is formed byelectric discharge by the plasma CVD method with a 20 to 200 Pa reactionpressure, a 300 to 400° C. substrate temperature at a high frequency(13.56 MHz) and a 0.1 to 1.0 W/cm² electric power density. Or it may beprovided by forming a hardened film containing one or a pluralityselected from the group consisting of a hydrogen, a nitrogen, a halidecarbon, a hydrogen fluoride and a rare gas by applying the plasmatreatment to the interlayer insulated film surface.

[0057] Thereafter, a wiring 311 is formed by forming a resist mask of adesired pattern and forming a contact hole reaching to the drainelectrode 307 of the current controlling TFT 308. As to the electrodematerial to be used here, a film is formed by the sputtering method ofthe vacuum deposition method with an Al, a Ti or an alloy materialthereof used as the conductive metal film, and it is patterned in adesired shape.

[0058] Next, a conductive film to serve as the anode of the luminescentelement will be formed. As the anode material, a transparent conductivefilm is used. As the transparent conductive film, a compound of anindium oxide and a tin oxide (it is referred to as an ITO), a compoundof an indium oxide and a zinc oxide, a tin oxide, a zinc oxide, or thelike can be used. The conductive film thickness at the time ispreferably 0.1 to 1 μm.

[0059] Thereafter, as shown in FIG. 4D, an anode 312 is formed byetching the transparent conductive film.

[0060] Then, as shown in FIG. 5A, an organic resin film comprising apolyimide, an acrylic and a polyimide amide is formed on the entiresurface. As to these materials, thermosetting materials to be hardenedby heating, or photosensitive materials to be hardened by theultraviolet ray irradiation can be adopted. In the case a thermosettingmaterial is used, an insulated layer 313 having an opening on the anode312 is formed by forming a resist mask and dry etching. In the case aphotosensitive material is used, an insulated film having an opening onthe node 312 is formed by executing exposure and the developingtreatment using a photo mask. In this specification, it is referred toas a bank 313. In either case, the bank 313 is formed so as to cover theend part of the anode 312 with the rim thereof in a tapered shape.

[0061] By providing the rim in a tapered shape, the covering property ofthe organic compound layer to be formed subsequently can be improved.

[0062] Next, an organic compound layer 314 is formed on the anode 312.The organic compound layer 314 can be formed by laminating in additionto the luminescent layer, a plurality of layers such as a positive holeinjecting layer, a positive hole transporting layer, a positive holeinhibiting layer, an electron transporting layer, an electron injectinglayer and a buffer layer in a combination. Moreover, the organiccompound layer 314 is formed in about a 10 to 150 nm thickness (FIG.5B). For the formation of the organic compound layer, in the case a lowmolecular based material is used, the deposition method is preferable,and in the case a polymer based material is used, the spin coatingmethod, the printing method, the ink-jet method, or the like can beused.

[0063] In this example, the organic compound layer 314 is formed on theanode 312 by the deposition method. The organic compound layer 314 ismade of organic compounds showing three kinds of light emissionincluding red, green and blue. Here, only the procedure of forming oneof them is shown. Moreover, the combination of the organic compound forforming the three kinds of the organic compound layers will be explainedbelow in detail.

[0064] The organic compound layer for the red light emission in thisexample can be made of an electron transporting organic compound, ablocking organic compound, a luminescent organic compound, a hostmaterial, a positive hole transporting organic compound, and a positivehole injecting organic compound.

[0065] Specifically, a tris(8-quinolinolato) aluminum (hereinafterreferred to as the Alq₃) as an electron transporting organic compound isformed in a 25 nm film thickness. A basocuproin (hereinafter referred toas the BCP) as a blocking organic compound is formed in a, 8 nm filmthickness. A 2,3,7,8,12,13,17,18-octaethyl-21H, 23H-porphyrin-platinum(hereinafter referred to as the PtOEP) as a luminescent organic compoundis co-deposited with a 4,4′-dicarbazol-biphenyl (hereinafter referred toas the CBP) to serve as the host in a 25 to 40 nm film thickness. A4,4′-bis[N-(1-naphthyl)-N-phenyl-amino]-biphen yl (hereinafter referredto as the α-NPD) as a positive hole transporting organic compound isformed in a 40 nm film thickness. And a copper phthalocyanine(hereinafter referred to as the Cu—Pc) as a positive hole injectingorganic compound is formed in a 15 nm film thickness. Thereby, a redluminescent organic compound layer can be formed.

[0066] Although the case of forming a red luminescent organic compoundlayer using 6 kinds of organic compounds with different functions isexplained here, the present invention is not limited thereto, and knownmaterials can be used as the organic compound showing the red lightemission.

[0067] A green luminescent organic compound layer in this example can beformed from an electron transporting organic compound, a blockingorganic compound, a luminescent organic compound, a host material, apositive hole transporting organic compound and a positive holeinjecting organic compound.

[0068] Specifically, an Alq₃ as an electron transporting organiccompound is formed in a 40 nm film thickness. A BCP as a blockingorganic compound is formed in a 10 nm film thickness. A CBP used as apositive hole transmitting host material is co-deposited with atris(2-phenyl pyridine) iridium (Ir(ppy)₃) in a 5 to 40 nm filmthickness. An α-NPD as a positive hole transporting organic compound isformed in a 10 nm film thickness. An MTDATA as a positive hole injectingorganic compound is formed in a 20 nm film thickness. And a Cu—Pc as apositive hole injecting organic compound is formed in a 10 nm filmthickness. Thereby, a green luminescent organic compound layer can beformed.

[0069] Although the case of forming a green luminescent organic compoundlayer using 7 kinds of organic compounds with different functions isexplained here, the present invention is not limited thereto, and knownmaterials can be used as the organic compound showing the green lightemission.

[0070] A blue luminescent organic compound layer in this example can beformed from an electron transporting organic compound, a blockingorganic compound, a luminescent organic compound and a positive holeinjecting organic compound.

[0071] Specifically, an Alq₃ as an electron transporting organiccompound is formed in a 40 nm film thickness. A BCP as a blockingorganic compound is formed in a 10 nm film thickness. An α-NPD as aluminescent organic compound is formed in a 40 nm film thickness. And aCu—Pc as a positive hole injecting organic compound is formed in a 20 nmfilm thickness. Thereby, a blue luminescent organic compound layer canbe formed.

[0072] Although the case of forming a blue luminescent organic compoundlayer using 4 kinds of organic compounds with different functions isexplained here, the present invention is not limited thereto, and knownmaterials can be used as the organic compound showing the blue lightemission.

[0073] By forming the above-mentioned organic compounds on the anode312, an organic compound layer showing the red light emission, the greenlight emission and the blue light emission can be formed in the pixelpart.

[0074] Moreover, as the organic compound for forming the organiccompound layer, a polymer based material can be used. As therepresentative polymer based materials, a polyparaphenylene vinylene(PPV) based material, a polyvinylcarbazol material (PVK) based material,a polyfluorene based material, or the like can be presented.

[0075] For example, for the organic compound layer to have the-red lightemission, a cyano polyphenylene vinylene, for the organic compound layerto have the green light emission, a polyphenylene vinylene, and for theorganic compound layer to have the blue light emission, a polyphenylenevinylene or a polyalkyl phenylene can be used.

[0076] Next, a cathode 315 is formed on the organic compound layer 314by the deposition method (see FIG. 5C). As the material for the cathode315, in addition to an MgAg alloy and an AlLi alloy, a film formed withelements belonging to the group I or group II in the periodic table bythe co-deposition method can be used as well. The film thickness of thecathode 315 is preferably about 80 to 200 nm.

[0077] Accordingly, an element substrate having an organic TFT, and aluminescent element 316 comprising the anode 312, the organic compoundlayer 314 and the cathode 315 of the present invention can be formed asshown in FIG. 3.

Example 2

[0078]FIG. 6A is a further detailed top view structure and FIG. 6B is acircuit diagram of the pixel part of the luminescent device explained inthe example 1 provided using the present invention. Since the commonnumerals are used in FIG. 6A and FIG. 6B, they can be referred to witheach other.

[0079] In this example, the TFT shown as the area 602 is referred to asthe switching TFT, and the TFT shown as the area 606 is referred to asthe current controlling TFT. Both of them comprise an organic TFT of thepresent invention. The source of the switching TFT 602 is connected witha source signal line 615, and the drain is connected with a drain wiring605. Moreover, the drain wiring 605 is connected electrically with agate electrode 607 of the current controlling TFT 606.

[0080] Furthermore, a channel area 604 of the switching TFT 602 isformed ion contact with the source and the drain, and it is superimposedwith a gate electrode connected electrically with a gate signal line603.

[0081] Moreover, the source of the current controlling TFT 606 isconnected electrically with a current supply line 616, and the drain isconnected electrically with a drain wiring 617. Furthermore, the drainwiring 617 is connected electrically with an anode (pixel electrode) 618shown by the dotted line.

[0082] The configuration of this example can be executed freely in acombination with the configuration of the example 1.

Example 3

[0083] In this example, a method for completing the element substrateshown in the example 1 as a luminescent device will be explained withreference to FIG. 10.

[0084]FIG. 10A is a top view of a luminescent device, and FIG. 10B is across-sectional view taken on the line A-A′ of FIG. 10A. The numeral1001 shown by the dotted line is a source signal line driving circuit,1002 a pixel part and 1003 a gate signal line driving circuit. Moreover,1004 is a cover material, 1005 a sealant, and the inside surrounded bythe sealant 1005 provides a space.

[0085] The numeral 1008 is a wiring for transmitting a signal inputtedinto the source signal line driving circuit 1001 and the gate signalline driving circuit 1003 and for receiving a video signal or a clocksignal from an FPC (flexible printed circuit) 1009 to serve as theexternal input terminal. Although only the FPC is shown here, a printedwiring board (PWB) may be attached to the FPC. The luminescent device inthis specification includes not only the main body of the luminescentdevice but also one in the state with the FPC or the PWB attachedthereto.

[0086] Next, the cross-sectional structure will be explained withreference to FIG. 10B. The pixel part 1002 and the source signal linedriving circuit 1001 as the driving circuit are formed above a substrate1010. The pixel part 1002 comprises a plurality of pixels including acurrent controlling TFT 1011 and an anode 1012 connected electricallywith the drain thereof.

[0087] Moreover, a bank 1013 is formed on both ends of the anode 1012.An organic compound layer 1014 is formed on the bank 1013 and the anode1012, and a cathode 1015 of a luminescent element 1016 is formed on thebank 1013 and the organic compound layer 1014.

[0088] The cathode 1015 serving also as a wiring provided commonly forall the pixels, is connected electrically with the FPC 1009 via thewiring 1008.

[0089] Moreover, the cover material 1004 is attached by the sealant1005. A spacer comprising a resin film can be provided for ensuring thedistance between the cover material 1004 and the luminescent element.The space 1007 in the sealant 1005 is filled with inert gas such asnitrogen. As the sealant 1005, an epoxy based resin can be usedpreferably.. Furthermore, the sealant 1005 is preferably a materialpermeating a moisture content or an oxygen as little as possible. Asubstance having a moisture absorbing effect or a substance having anoxidation preventing effect can be contained in the space 1007.

[0090] Moreover, in this example, as the material comprising the covermaterial 1004, in addition to a glass substrate and a quartz substrate,a plastic substrate made of an FRP (fiberglass-reinforced plastic), aPVF (polyvinyl fluoride), a Mylar, a polyester, an acrylic, or the likecan be used.

[0091] Furthermore, it is also possible to seal with the sealant so asto cover the side surface (exposed surface) after bonding the covermaterial 1004 using the sealant 1005.

[0092] By sealing the luminescent element in the space 1007 as mentionedabove, the luminescent element can be blocked completely from theoutside so that entrance of a substance promoting deterioration of theorganic compound layer, such as a moisture content and an oxygen fromthe outside can be prevented. Therefore, a highly reliable luminescentelement can be obtained.

[0093] The configuration of this example can be executed freely in acombination with the configuration of the example 1 or the example 2.

Example 4

[0094] In this example, liquid crystal display device of active matrixdriving method using the organic TFT explained in the embodiment of thepresent invention will be explained. An example of the pixel structuresuitable for the liquid crystal display device is shown in FIG. 7, andthe process of manufacturing will be explained with reference to thecross-sectional view of FIG. 8. Furthermore, with reference to the topview of FIG. 9, the liquid crystal display device of this example willbe explained.

[0095] In FIG. 7, a first interlayer insulated film 705 is formed via agate insulated film 704 on a gate electrode 702 and a first capacityelectrode 703 formed on a substrate 701. The first interlayer insulatedfilm 705 has an opening part on the gate electrode 702, with a channelarea 706 formed in the opening part. Furthermore, a source electrode 707and a drain electrode 708 are formed in contact with the firstinterlayer insulated film 705 and the channel area 706. In this example,the source electrode 707 and the drain electrode 708 are formed, and atthe same time, a second capacity electrode 709 is formed. In thisexample, the organic TFT formed in the pixel part is referred to as thepixel TFT 710.

[0096] After the formation of the source electrode 707 and the drainelectrode 708, a passivation film 711comprising a silicon nitride film,and a second interlayer insulated film 712 comprising an organic resinmaterial selected from the group consisting of an acrylic, a polyimide,a polyamide and a polyimide amide, are formed. Thereafter, a wiring 713and a pixel electrode 714 are formed by providing a hole.

[0097] Although only the pixel part is shown here, a driving circuit anda pixel part with the organic TFT formed on the same substrate areformed. In the driving circuit, according to the organic TFT, a shiftregister circuit, a buffer circuit, a level shifter circuit, a latchcircuit, or the like can be formed.

[0098] In the pixel part, a capacity part to be connected with the pixelTFT 710 comprises the first capacity electrode 703, the first interlayerinsulated film 705 and the second capacity electrode 709. The firstcapacity electrode 703 is connected electrically with a gate line so asto provide a capacity part 715 together with the second capacityelectrode 709.

[0099]FIG. 9 is a top view of the pixel part in this state, wherein theline A-A′ corresponds to FIG. 8C. The source electrode 707 of the pixelTFT 710 is connected with a source signal line 901, and the gateelectrode 702 is connected with a gate signal line 902.

[0100] After formation to the step of FIG. 8C, as shown in FIG. 8D, acounter electrode 717 is formed on a counter substrate 716. Anorientation film 718 is formed thereon, and a rubbing treatment isapplied thereto. The counter electrode 717 is made of an ITO. Moreover,although it is not shown, a columnar spacer may be formed at a desiredposition for maintaining the substrate distance by patterning an organicresin film such as an acrylic resin film before formation of theorientation film 718. Furthermore, a spherical spacer may be scatteredon the substrate entire surface instead of the columnar spacer.

[0101] Then, the counter substrate 716 is attached with the substrate.Thereafter, a liquid crystal material 719 is injected between thesubstrates, and they are sealed completely by a sealant (not shown). Asthe liquid crystal material, a known liquid crystal material can beused. Accordingly, liquid crystal display device by active matrixdriving method shown in FIG. 7 can be completed.

Example 5

[0102] The semiconductor device of the present invention can be appliedto various electronic devices.

[0103] Such electronic devices using the present invention include avideo camera, a digital camera, a goggles-type display (head mountdisplay), a navigation system, a sound reproduction device (a car audioequipment and an audio set), a lap-top computer, a game machine, aportable information terminal (a mobile computer, a portable telephone,a portable game machine, an electronic book, or the like), an imagereproduction apparatus including a recording medium (more specifically,an apparatus which can reproduce a recording medium such as a digitalversatile disc (DVD) and so forth, and includes a display for displayingthe reproduced image), or the like. In FIGS. 11A to 11H respectivelyshows various specific examples of such electronic devices.

[0104]FIG. 11A illustrates an organic luminescent display device whichincludes a casing 2001, a support table 2002, a display portion 2003, aspeaker portion 2004, a video input terminal 2005 or the like. Thepresent invention is applicable to the display portion 2003. The displaydevice is including all of the display device for displayinginformation, such as a personal computer, a receiver of TV broadcastingand an advertising display.

[0105]FIG. 11B illustrated a digital still camera which includes a mainbody 2101, a display portion 2102, an image receiving portion 2103, anoperation key 2104, an external connection port 2105, a shutter 2106, orthe like. The present invention can be used as the display portion 2102and other circuits.

[0106]FIG. 11C illustrates a lap-top computer which includes a main body2201, a casing 2202, a display portion 2203, a keyboard 2204, anexternal connection port 2205, a pointing mouse 2206, or the like. Thepresent invention can be used as the display portion 2203 and othercircuits.

[0107]FIG. 11D illustrated a mobile computer which includes a main body2301, a display portion 2302, a switch 2303, an operation key 2304, aninfrared port 2305, or the like. The present invention can be used asthe display portion 2302 and other circuits.

[0108]FIG. 11E illustrates an image reproduction apparatus including arecording medium (more specifically, a DVD reproduction apparatus),which includes a main body 2401, a casing 2402, a display portion A2403, another display portion B 2404., a recording medium (DVD or thelike) reading portion 2405, an operation key 2406, a speaker portion2407 or the like. The display portion A 2403 is used mainly fordisplaying image information, while the display portion B 2404 is usedmainly for displaying character information. The present invention canbe used as these display portions A 2403, B 2404 and other circuits. Theimage reproduction apparatus including a recording medium furtherincludes a game machine or the like.

[0109]FIG. 1F illustrates a goggle type display (head mounted display)which includes a main body 2501, a display portion 250.2, an arm portion2503. The present invention can be used as the display portion 2502 andother circuits.

[0110]FIG. 11G illustrates a video camera which includes a main body2601, a display portion 2602, a casing 2603, an external connecting port2604, a remote control receiving portion 2605, an image receivingportion 2606, a battery 2607, a sound input portion 2608, an operationkey 2609, or the like. The present invention can be used as the displayportion 2602 other circuits.

[0111]FIG. 11H illustrates a mobile phone which includes a main body2701, a casing 2702, a display portion 2703, a sound input portion 2704,a sound output portion 2705, an operation key 2706, an externalconnecting port 2707, an antenna 2708, or the like. The presentinvention can be used as the display portion 2703 and other circuits.

[0112] In addition, the front type projector and the rear type projectorusing a liquid crystal display device that is one of the organicsemiconductor devices of the present invention may be included inelectronic devices of the present invention. When the brighter luminanceof light emitted from the organic luminescent material becomes availablein the future, the present invention will be applicable to a front-typeor rear-type projector in which light including output image informationis enlarged by means of lenses or the like to be projected.

[0113] The application range of the present invention is quite large, sothat the present invention can be used to various kinds of electronicdevices. Further, this embodiment can be implemented by freely combiningwith the structure of Embodiments 1 to 4.

[0114] Since an organic TFT using an organic semiconductor material canbe formed by executing the present invention, manufacturing by a lowtemperature process can be enabled so that the width of selecting thematerial used for the manufacturing can be widened. Moreover, sincepatterning of a soluble organic semiconductor material can be enabled,the size of the organic TFT can be made further smaller. Thereby, ahighly sophisticated organic semiconductor device can be formed comparedwith the case of using the ink-jet method or the printing method, whichhave conventionally been used.

What is claimed is:
 1. An organic semiconductor device using an organicthin film transistor comprising: a first electrode formed in contactwith an insulated surface, a first insulated film formed in contact withthe first electrode, a second insulated film formed in contact with thefirst insulated film, having an opening part at a position superimposedon the first electrode, an organic semiconductor film formed in theopening part, and a second electrode and a third electrode formed incontact with the organic semiconductor film, wherein the organicsemiconductor film and the second insulated film form the same surface.2. A device according to claim 1, wherein the organic semiconductor filmis made of a soluble organic semiconductor material.
 3. A deviceaccording to claim 1, wherein the organic semiconductor film has a filmthickness thicker than that of the second insulated film.
 4. A deviceaccording to claim 1, wherein the second electrode and the thirdelectrode are made of the same metal having a large work function.
 5. Adevice according to claim 4, wherein the second electrode and the thirdelectrode comprise a metal selected from the group consisting of gold,platinum, chromium, palladium, aluminum, indium, molybdenum and nickel.6. A device according to claim 1, wherein the organic semiconductordevice is incorporated into one selected from the group consisting of adisplay device, a digital still camera, a laptop personal computer, amobile computer, a portable image reproducing device comprising arecording medium, a goggle type display, a video camera and a portablephone.
 7. An organic semiconductor device using an organic thin filmtransistor comprising: a first electrode formed in contact with aninsulated surface, a first insulated film formed in contact with thefirst electrode, a second insulated film formed in contact with thefirst insulated film, having an opening part at a position superimposedon the first electrode, an organic semiconductor film formed in theopening part, and a second electrode and a third electrode formed incontact with the organic semiconductor film, wherein the secondelectrode and the third electrode are formed without contact with eachother.
 8. A device according to claim 7, wherein the organicsemiconductor film is made of a soluble organic semiconductor material.9. A device according to claim 7, wherein the organic semiconductor filmhas a film thickness thicker than that of the second insulated film. 10.A device according to claim 7, wherein the second electrode and thethird electrode are made of the same metal having a large work function.11. A device according to claim 10, wherein the second electrode and thethird electrode comprise a metal selected from the group consisting ofgold, platinum, chromium, palladium, aluminum, indium, molybdenum andnickel.
 12. A device according to claim 7, wherein the organicsemiconductor device is incorporated into one selected from the groupconsisting of a display device, a digital still camera, a laptoppersonal computer, a mobile computer, a portable image reproducingdevice comprising a recording medium, a goggle type display, a videocamera and a portable phone.
 13. An organic semiconductor device usingan organic thin film transistor comprising: a first electrode formed incontact with an insulated surface, a first insulated film formed incontact with the first electrode, a second insulated film formed incontact with the first insulated film, having an opening part at aposition superimposed on the first electrode, an organic semiconductorfilm formed in the opening part, and a second electrode and a thirdelectrode formed in contact with the organic semiconductor film, whereinthe second insulated film has a tapered rim.
 14. A device according toclaim 13, wherein the organic semiconductor film is made of a solubleorganic semiconductor material.
 15. A device according to claim 13,wherein the organic semiconductor film has a film thickness thicker thanthat of the second insulated film.
 16. A device according to claim 13,wherein the second electrode and the third electrode are made of thesame metal having a large work function.
 17. A device according to claim15, wherein the second electrode and the third electrode comprise ametal selected from the group consisting of gold, platinum, chromium,palladium, aluminum, indium, molybdenum and nickel.
 18. A deviceaccording to claim 13, wherein the organic semiconductor device isincorporated into one selected from the group consisting of a displaydevice, a digital still camera, a laptop personal computer, a mobilecomputer, a portable image reproducing device comprising a recordingmedium, a goggle type display, a video camera and a portable phone. 19.An organic semiconductor device using an organic thin film transistorcomprising: a first electrode formed in contact with an insulatedsurface, a first insulated film formed in contact with the firstelectrode, a second insulated film formed in contact with the firstinsulated film, having an opening part at a position superimposed on thefirst electrode, an organic semiconductor film formed in the openingpart, and a second electrode and a third electrode formed in contactwith the organic semiconductor film, wherein the organic semiconductorfilm is formed in contact with the first insulated film.
 20. A deviceaccording to claim 19, wherein the organic semiconductor film is made ofa soluble organic semiconductor material. 21 A device according to claim19, wherein the organic semiconductor film has a film thickness thickerthan that of the second insulated film.
 22. A device according to claim19, wherein the second electrode and the third electrode are made of thesame metal having a large work function.
 23. A device according to claim22, wherein the second electrode and the third electrode comprise ametal selected from the group consisting of gold, platinum, chromium,palladium, aluminum, indium, molybdenum and nickel.
 24. A deviceaccording to claim 19, wherein the organic semiconductor device isincorporated into one selected from the group consisting of a displaydevice, a digital still camera, a laptop personal computer, a mobilecomputer, a portable image reproducing device comprising a recordingmedium, a goggle type display, a video camera and a portable phone
 25. Asemiconductor device comprising: a gate electrode provided over asubstrate; a gate insulator comprising a first insulating film and asecond insulating film, said first insulating film provided over saidgate electrode, said second insulating film provided over said firstinsulating film, said second insulating film provided with an openingpart at a position superimposed over said gate electrode; a channelregion provided over said gate electrode with said gate insulatortherebetween, said channel region provided in an organic semiconductorfilm provided in said opening part; a source electrode and a drainelectrode provided in contact with said organic semiconductor film,wherein said organic semiconductor film and said second insulating filmform a same surface.
 26. A device according to claim 25, wherein thesource electrode and the drain electrode comprise a metal selected fromthe group consisting of gold, platinum, chromium, palladium, aluminum,indium, molybdenum and nickel.
 27. A device according to claim 25,wherein said semiconductor device is incorporated into one selected fromthe group consisting of a display device, a digital still camera, alaptop personal computer, a mobile computer, a portable imagereproducing device comprising a recording medium, a goggle type display,a video camera and a portable phone.
 28. A semiconductor devicecomprising: a gate electrode provided over a substrate; a gate insulatorcomprising a first insulating film and a second insulating film, saidfirst insulating film provided over said gate electrode, said secondinsulating film provided over said first insulating film, said secondinsulating film provided with an opening part at a position superimposedover said gate electrode; a channel region provided over said gateelectrode with said gate insulator therebetween, said channel regionprovided in an organic semiconductor film provided in said opening part;a source electrode and a drain electrode provided in contact with saidorganic semiconductor film, wherein a rim of said opening part istapered.
 29. A device according to claim 28, wherein the sourceelectrode and the drain electrode comprise a metal selected from thegroup consisting of gold, platinum, chromium, palladium, aluminum,indium, molybdenum and nickel.
 30. A device according to claim 28,wherein said semiconductor device is incorporated into one selected fromthe group consisting of a display device, a digital still camera, alaptop personal computer, a mobile computer, a portable imagereproducing device comprising a recording medium, a goggle type display,a video camera and a portable phone.
 31. A semiconductor devicecomprising: a gate electrode provided over a substrate; a gate insulatorcomprising a first insulating film and a second insulating film, saidfirst insulating film provided over said gate electrode, said secondinsulating film provided over said first insulating film said secondinsulating film provided with an opening part at a position superimposedover said gate electrode; a channel region provided over said gateelectrode with said gate insulator therebetween, said channel regionprovided in an organic semiconductor film provided in said opening part;a source electrode and a drain electrode provided in contact with saidorganic semiconductor film, wherein said organic semiconductor film isprovided in contact with said first insulating film.
 32. A deviceaccording to claim 31, wherein the source electrode and the drainelectrode comprise a metal selected from the group consisting of gold,platinum, chromium, palladium, aluminum, indium, molybdenum and nickel.33. A device according to claim 31, wherein said semiconductor device isincorporated into one selected from the group consisting of a displaydevice, a digital still camera, a laptop personal computer, a mobilecomputer, a portable image reproducing device comprising a recordingmedium, a goggle type display, a video camera and a portable phone.